Instrumentation and control (I&C) service companies keep the measuring and control systems of industrial plants working: pressure and temperature transmitters, flow meters, level instruments, analysers, control valves, interlocks and the loops that connect them to control systems. Their clients — process plants, utilities, pharma, food, oil and gas, power — expect accurate work, traceable records and fast turnaround during shutdowns. Managing hundreds of instrument tags across many client sites with spreadsheets and paper datasheets is slow and risky.
The types of I&C work
- Periodic calibration of field instruments on site or in a workshop.
- Loop checks — verifying the full signal path from field instrument to control system display and back to final elements.
- Control valve service — stroke testing, positioner calibration, overhaul.
- Breakdown support — faulty readings, failed transmitters, trips.
- Shutdown and turnaround work — large scopes in short windows.
- Installation and commissioning of new instruments and systems.
- Annual maintenance contracts with resident or visiting engineers.
Instrument register by client and tag
Everything starts with an accurate register for each client site: area, system, tag number, instrument type, range, units, make, model, serial number, location and criticality. Tag numbers are how plant people talk about instruments, so search and records should be organised by tag. Linking datasheets, loop diagrams and previous calibration results to each tag saves enormous time on site.
Calibration jobs
For each instrument due, a job carries the calibration procedure: test points, tolerance, method and reference standards required. On site, the technician records:
- As-found readings at each test point.
- Adjustments made.
- As-left readings.
- Pass/fail against tolerance, calculated automatically.
- Reference standards used, with their serial numbers.
- Environmental conditions where relevant.
- Photos and remarks.
As-found failures matter to the client: they may affect product quality or safety decisions made since the last calibration. Flagging them clearly in the report helps clients start their own impact assessment.
Reference standards and traceability
An I&C company's credibility depends on its own reference standards — pressure calibrators, temperature baths, multifunction calibrators — being calibrated and within date. Tracking each standard's calibration certificate and due date, and blocking or warning when an overdue standard is selected on a job, protects both the company and its clients. Certificates can then show the traceability chain for every result.
Loop checks
Loop checks involve the field technician and someone at the control system working together. Digital loop-check sheets with each point — field value injected, control system reading, alarm and trip settings, final element response — allow both sides to record results in one place, often with the control room confirming on their own device. Exceptions become punch-list items with owners.
Shutdown and turnaround planning
During a shutdown, an I&C contractor may need to complete hundreds of tasks in days. Software helps by:
- Importing the client's scope list by tag.
- Grouping tasks by area, permit and crew.
- Assigning crews and tracking progress live.
- Recording results as work is done, not typed up afterwards.
- Showing a dashboard of completed, in progress, blocked and pending tasks for daily meetings with the client.
Certificates and reports
Clients need certificates per instrument and summary reports per visit or shutdown. Generating them from recorded data — with the company's template, authorised signatory and reference standard details — removes days of office work and reduces transcription errors. Many clients appreciate access to a portal where they can download any certificate for their plant.
Contracts and resident engineers
Some contracts station engineers at the client's plant. Their daily work — calibrations, breakdowns, small modifications — can be recorded through the same mobile app, giving the client a monthly report of work done and the I&C company a clear view of hours spent per contract.
Technician competence
Different instruments and sites require different skills and site-specific trainings or safety passes. Recording each technician's competencies and site authorisations with expiry dates helps planners assign the right people.
An example
An I&C service company supporting chemical and pharma plants kept calibration results on paper datasheets typed into certificates afterwards. During shutdowns, the office worked late every night producing reports. After moving to a field app with tag-based registers, digital calibration sheets and automatic certificates, reports were available the same day, as-found failures were flagged instantly to the client, and the company could show standard traceability on every certificate.
What to look for
- Client site and tag-based instrument registers.
- Calibration procedures with test points and tolerances.
- As-found/as-left recording with automatic pass/fail.
- Reference standard tracking with due-date checks.
- Digital loop-check sheets.
- Shutdown scope import and progress tracking.
- Automatic certificates and client portal.
- Technician competence and site authorisation records.
Corposol builds field service software for industrial service companies. Talk to us about your I&C operation.
Workshop calibration and instrument logistics
Some instruments are removed from the plant and calibrated in the workshop. Tracking each instrument out of the plant and back — with tag, condition on receipt, calibration results and return date — avoids lost instruments and makes sure spares installed temporarily are recorded. Clients see exactly where every removed instrument is at any time.
Trend data across visits
Because as-found results are recorded per tag, the history shows which instruments drift most between calibrations. Instruments that are consistently within tolerance may justify longer intervals where the client's quality system allows it, while those that often fail as-found may need shorter intervals, replacement or investigation of installation conditions.
Frequently asked questions
Can we manage instruments by client plant and tag number?
Yes. Each client site can hold its areas, systems and instrument tags with type, range, make, model, serial and location.
Can technicians record as-found and as-left readings?
Yes. Calibration checklists capture test points, as-found and as-left values, tolerances and pass/fail results, with the reference standards used.
Can certificates be generated automatically?
Yes. Certificates and reports can be generated from the recorded results using your templates, and shared with the client.
Can it track our own reference standards?
Yes. Your standards and test equipment can be tracked with their own calibration due dates, and the software can warn if an overdue standard is selected.
Can it handle shutdown projects?
Yes. Shutdown scopes with hundreds of instrument tasks can be planned, assigned to crews and tracked with progress dashboards.
